Radar systems with Built-In Test (BIT) target generators typically provide only limited target detection test capability. Excessive phase noise within the Stable Local Oscillator (STALO) of a radar system can significantly impact target detection in pulse Doppler and moving target indicator radars. Once a radar system leaves the factory, it typically is not screened for phase noise ever again. As components within the radar system degrade, they can affect phase noise and overall system performance, often adversely, without exhibiting functional failures or any indication to an operator.